[PATCH 50/92] clocksource/drivers/atmel-pit: Convert init function to return error

From: Daniel Lezcano
Date: Tue Jun 28 2016 - 06:34:08 EST


The init functions do not return any error. They behave as the following:

- panic, thus leading to a kernel crash while another timer may work and
make the system boot up correctly

or

- print an error and let the caller unaware if the state of the system

Change that by converting the init functions to return an error conforming
to the CLOCKSOURCE_OF_RET prototype.

Proper error handling (rollback, errno value) will be changed later case
by case, thus this change just return back an error or success in the init
function.

Signed-off-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
---
drivers/clocksource/timer-atmel-pit.c | 43 +++++++++++++++++++++++------------
1 file changed, 29 insertions(+), 14 deletions(-)

diff --git a/drivers/clocksource/timer-atmel-pit.c b/drivers/clocksource/timer-atmel-pit.c
index d911c5d..ffaca7c 100644
--- a/drivers/clocksource/timer-atmel-pit.c
+++ b/drivers/clocksource/timer-atmel-pit.c
@@ -177,7 +177,7 @@ static irqreturn_t at91sam926x_pit_interrupt(int irq, void *dev_id)
/*
* Set up both clocksource and clockevent support.
*/
-static void __init at91sam926x_pit_common_init(struct pit_data *data)
+static int __init at91sam926x_pit_common_init(struct pit_data *data)
{
unsigned long pit_rate;
unsigned bits;
@@ -204,14 +204,21 @@ static void __init at91sam926x_pit_common_init(struct pit_data *data)
data->clksrc.rating = 175;
data->clksrc.read = read_pit_clk;
data->clksrc.flags = CLOCK_SOURCE_IS_CONTINUOUS;
- clocksource_register_hz(&data->clksrc, pit_rate);
+
+ ret = clocksource_register_hz(&data->clksrc, pit_rate);
+ if (ret) {
+ pr_err("Failed to register clocksource");
+ return ret;
+ }

/* Set up irq handler */
ret = request_irq(data->irq, at91sam926x_pit_interrupt,
IRQF_SHARED | IRQF_TIMER | IRQF_IRQPOLL,
"at91_tick", data);
- if (ret)
- panic(pr_fmt("Unable to setup IRQ\n"));
+ if (ret) {
+ pr_err("Unable to setup IRQ\n");
+ return ret;
+ }

/* Set up and register clockevents */
data->clkevt.name = "pit";
@@ -226,34 +233,42 @@ static void __init at91sam926x_pit_common_init(struct pit_data *data)
data->clkevt.resume = at91sam926x_pit_resume;
data->clkevt.suspend = at91sam926x_pit_suspend;
clockevents_register_device(&data->clkevt);
+
+ return 0;
}

-static void __init at91sam926x_pit_dt_init(struct device_node *node)
+static int __init at91sam926x_pit_dt_init(struct device_node *node)
{
struct pit_data *data;

data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data)
- panic(pr_fmt("Unable to allocate memory\n"));
+ return -ENOMEM;

data->base = of_iomap(node, 0);
- if (!data->base)
- panic(pr_fmt("Could not map PIT address\n"));
+ if (!data->base) {
+ pr_err("Could not map PIT address\n");
+ return -ENXIO;
+ }

data->mck = of_clk_get(node, 0);
if (IS_ERR(data->mck))
/* Fallback on clkdev for !CCF-based boards */
data->mck = clk_get(NULL, "mck");

- if (IS_ERR(data->mck))
- panic(pr_fmt("Unable to get mck clk\n"));
+ if (IS_ERR(data->mck)) {
+ pr_err("Unable to get mck clk\n");
+ return PTR_ERR(data->mck);
+ }

/* Get the interrupts property */
data->irq = irq_of_parse_and_map(node, 0);
- if (!data->irq)
- panic(pr_fmt("Unable to get IRQ from DT\n"));
+ if (!data->irq) {
+ pr_err("Unable to get IRQ from DT\n");
+ return -EINVAL;
+ }

- at91sam926x_pit_common_init(data);
+ return at91sam926x_pit_common_init(data);
}
-CLOCKSOURCE_OF_DECLARE(at91sam926x_pit, "atmel,at91sam9260-pit",
+CLOCKSOURCE_OF_DECLARE_RET(at91sam926x_pit, "atmel,at91sam9260-pit",
at91sam926x_pit_dt_init);
--
1.9.1